U.S. patent number 10,910,003 [Application Number 15/598,909] was granted by the patent office on 2021-02-02 for process coupons used in manufacturing flexures.
This patent grant is currently assigned to Hutchinson Technology Incorporated. The grantee listed for this patent is Hutchinson Technology Incorporated. Invention is credited to Brian D. Boudreau, Kurt C. Swanson.
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United States Patent |
10,910,003 |
Swanson , et al. |
February 2, 2021 |
Process coupons used in manufacturing flexures
Abstract
A system and methods for manufacturing devices such as flexures
using process coupons are described are described. The method
including performing a test on at least one feature of a coupon,
the coupon is included on an assembly sheet used in manufacturing
flexures. The at least one feature is produced by a manufacturing
processing step that is used to produce a portion of a flexure.
And, the physical characteristics of the feature include at least
one physical characteristic that is different than physical
characteristics of the portion. The method also including
determining the manufacturing processing step will produce an
abnormal portion of a flexure based on the performed test. Further,
the method includes adjusting the manufacturing processing step and
manufacturing a portion of a flexure using the adjusted
manufacturing processing step.
Inventors: |
Swanson; Kurt C. (Chippewa
Falls, WI), Boudreau; Brian D. (Charlotte, NC) |
Applicant: |
Name |
City |
State |
Country |
Type |
Hutchinson Technology Incorporated |
Hutchinson |
MN |
US |
|
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Assignee: |
Hutchinson Technology
Incorporated (Hutchinson, MN)
|
Family
ID: |
1000005337519 |
Appl.
No.: |
15/598,909 |
Filed: |
May 18, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
|
US 20180005655 A1 |
Jan 4, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62338118 |
May 18, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G11B
5/484 (20130101); G11B 5/3166 (20130101); G11B
5/4833 (20130101) |
Current International
Class: |
G11B
5/127 (20060101); G11B 5/31 (20060101); H04R
31/00 (20060101); G11B 5/48 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
International Search Report and Written Opinion in International
Application No. PCT/US2017/033410, dated Oct. 30, 2017. cited by
applicant .
International Preliminary Report on Patentability in International
Application No. PCT/US2017/033410, dated Nov. 29, 2018. cited by
applicant .
Office Action in Chinese patent application No. 201780044298.8,
dated Apr. 3, 2010. cited by applicant.
|
Primary Examiner: Kim; Paul D
Attorney, Agent or Firm: DLA Piper LLP (US)
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent
Application No. 62/338,118, filed on May 18, 2016, which is hereby
incorporated by reference in its entirety.
Claims
What is claimed is:
1. A coupon located on an assembly sheet, the assembly sheet
including at least one first section including a flexure and at
least one second section including the coupon, the coupon
comprising: at least one first feature formed on the at least one
second section of the assembly sheet, the at least one first
feature includes a shared physical characteristic as a formed
portion of the flexure, the at least one first feature is
configured to be tested to indicate whether the formed portion of
the flexure is abnormal; and at least one second feature formed on
the assembly sheet that includes a physical characteristic that is
different than physical characteristics of the portion of the
flexure.
2. The coupon of claim 1, wherein the shared physical
characteristic includes at least one of: size, height, thickness,
width, diameter, conductivity, resistance, reflectivity, adhesion,
side slope, and color.
3. The coupon of claim 1, wherein the physical characteristic that
is different than physical characteristics of the portion of the
flexure includes at least one of: size, height, thickness, width,
diameter, conductivity, resistance, reflectivity, adhesion, side
slope, and color of the at least one feature.
4. The coupon of claim 1, wherein the shared physical
characteristic is configured to be tested using at least one of: a
vision test, an electrical test, a spectroscopy test and a white
light interferometer test.
5. The coupon of claim 1, wherein the at least one second feature
includes varying sizes of at least one of: a plurality of circular
dots, a plurality of circular holes, a plurality of horizontal
rectangles, a plurality of horizontal rectangular troughs, a
plurality of vertical rectangles, a plurality of vertical
rectangular troughs, registration layers, a star pattern, a
plurality of ground features, and a spiraled conductor.
6. The coupon of claim 1, wherein the at least one second feature
includes a similar set of features, each of the similar set of
features having a range of different dimensions.
7. The coupon of claim 6, wherein the similar set of features is at
least one of: a set of holes, a set of dots having a range of
different diameters, a set of horizontal rectangles having a range
of different widths, a set of horizontal rectangular troughs having
a range of different widths, a set of vertical rectangles having a
range of different widths and a set of vertical rectangular troughs
having a range of different widths.
8. The coupon of claim 1, wherein the at least one first feature
formed on the assembly sheet using at least one of: applying a
dielectric layer, applying a conductive layer, applying a backing
layer, etching a base layer, etching a dielectric layer, etching a
conductive layer and etching a backing layer.
9. The coupon of claim 1, wherein the at least one second section
where the coupon is located is proximate to at least one of: a
border of the assembly sheet, between a row of flexures, between a
column of flexures and on a carrier strip of the assembly sheet.
Description
FIELD
Embodiments of the invention relate generally to manufacturing
techniques. More particularly, embodiments of the invention relates
to using a coupon in the manufacturing of flexures.
BACKGROUND
Flexures generally consist of a spring metal base layer (e.g.,
stainless steel ("SST")), a conductive trace layer (e.g., copper
(Cu)) on one side of the base layer, which is separated from the
base layer by an insulating layer (e.g., a dielectric). An
insulating covercoat can be applied over all or portions of the
conductive layer. Corrosion resistant metals such as gold (Au)
and/or nickel (Ni) can be plated or otherwise applied to portions
of the trace layer to provide corrosion resistance. Conventional
additive deposition and/or subtractive processes such as wet (e.g.,
chemical) and dry (e.g., plasma) etching, electro plating and
electroless plating and sputtering processes in connection with
photolithography (e.g., use of patterned and/or unpatterned
photoresist masks) can be used to manufacture the flexures in
accordance with embodiments of the disclosure. The term "formed"
may be used in this application to describe one or more of these
processes. In addition, mechanical methods (e.g., using punches and
bends) can also be used to manufacture the flexures in accordance
with embodiments of the disclosure.
Additive and subtractive processes of these types are, for example,
known and used in connection with the manufacture of disk drive
head suspensions, and are disclosed generally in the following U.S.
patents, all of which are incorporated herein by reference for all
purposes: Bennin et al., U.S. Pat. No. 8,885,299, entitled "Low
Resistance Ground Joints for Dual Stage Actuation Disk Drive
Suspensions;" Rice et al., U.S. Pat. No. 8,169,746, entitled
"Integrated Lead Suspension with Multiple Trace Configurations;"
Hentges et al., U.S. Pat. No. 8,144,430, entitled "Multi-Layer
Ground Plane Structures for Integrated Lead Suspensions;" Hentges
et al., U.S. Pat. No. 7,929,252, entitled "Multi-Layer Ground Plane
Structures for Integrated Lead Suspensions;" Swanson et al., U.S.
Pat. No. 7,388,733, entitled "Method for Making Noble Metal
Conductive Leads for Suspension Assemblies;" Peltoma et al., U.S.
Pat. No. 7,384,531, entitled "Plated Ground Features for Integrated
Lead Suspensions."
As stated above, a number of manufacturing steps are completed to
form the layers of the flexures into components having the
dimensional and performance requirements needed. As various
manufacturing processing steps are completed to form the layers of
the flexures, variations can occur making the flexure unable to
perform as required. As such, there remains a continuing need for
improved manufacturing processes of flexures.
SUMMARY
A system and methods for manufacturing devices such as flexures
using process coupons are described. The method including
performing a test on at least one feature of a coupon, the coupon
is included on an assembly sheet used in manufacturing flexures.
The at least one feature is produced by a manufacturing processing
step that is used to produce a portion of a flexure. And, the
physical characteristics of the feature include at least one
physical characteristic that is different than physical
characteristics of the portion. The method also including
determining the manufacturing processing step will produce an
abnormal portion of a flexure based on the performed test. Further,
the method includes adjusting the manufacturing processing step and
manufacturing a portion of a flexure using the adjusted
manufacturing processing step.
Other features and advantages of embodiments of the present
invention will be apparent from the accompanying drawings and from
the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention are illustrated by way of
example and not limitation in the figures of the accompanying
drawings, in which like references indicate similar elements and in
which:
FIG. 1 illustrates a block diagram of a system for using a process
coupon to manufacture flexures according to an embodiment;
FIG. 2 illustrates an example assembly sheet according to an
embodiment;
FIG. 3 illustrates a top-down view of a portion of the assembly
sheet including a coupon according to an embodiment;
FIG. 4 illustrates coupons according to embodiments;
FIG. 5 illustrates coupons according to embodiments;
FIG. 6 illustrates coupons according to embodiments;
FIG. 7 illustrates coupons according to embodiments;
FIG. 8 illustrates a plurality of the coupons according to
embodiments; and
FIG. 9 illustrates a diagram of a data management process flow
according to an embodiment.
Although the term "block" may be used herein to connote different
elements illustratively employed, the term should not be
interpreted as implying any requirement of, or particular order
among or between, various steps disclosed herein unless and except
when explicitly referring to the order of individual steps.
Additionally, a "set" or "group" of items (e.g., inputs,
algorithms, data values, etc.) may include one or more items, and,
similarly, a subset or subgroup of items may include one or more
items.
DETAILED DESCRIPTION
FIG. 1 is a block diagram of an illustrative system 100 for using
process coupons to manufacture devices including, but limited to,
flexures according to various embodiments. The system 100 depicts a
simplified illustration of a roll-to-roll manufacturing system 100
used to produce a plurality of flexures. As described above,
flexures may be used in disk drive head suspensions. In addition,
the techniques and methods describe herein can be used to
manufacture devices, such as flexures of actuator assemblies, such
as shape memory allow actuators used in autofocus and optical image
stabilization assemblies.
The system 100 includes a substrate 102. In embodiments, the
substrate 102 is a base layer (e.g., SST) that may be partitioned
into a plurality of assembly sheets 104A-104I. On each assembly
sheet 104A-104I, one or more flexures 106A-106L and coupons
108A-108H may be formed. The flexures 106A-106L and coupons
108A-108H depicted are for illustrative purposes and are not drawn
to scale. Each coupon of the coupons 108A-108H may include a
plurality of different coupons having different features. For
example, each coupon of the coupons 108A-108H may include one or
more of the coupons 302A-302E depicted in FIG. 3 and/or include one
or more of the coupons described in FIGS. 4-8 below. To form the
flexures 106A-106L, the substrate 102 may pass from a first roll
110A to a second roll 110B and vice-versa. When passing between the
first roll 110A and the second roll 110B, the substrate 102
transitions through a manufacturing machine 112.
The manufacturing machine 112 may form the flexures 106A-106L
using, for example, additive deposition and/or subtractive
processes such as wet (e.g., chemical) and dry (e.g., plasma)
etching, electro plating and electroless plating and sputtering
processes in connection with photolithography. The processes used
to form the flexures 106A-106L may also form one or more features
included in the coupons 108A-108H. That is, the manufacturing
machine 112 may deposit, etch, expose and/or develop one or more
layers of material on to the substrate 102 to form the flexures
106A-106L and coupons 108A-108H. For example, the manufacturing
machine 112 may deposit one or more dielectric layers (e.g.,
polyimide) and/or one or more conductive layers (e.g., copper,
chrome, nickel, gold and/or the like) on the substrate 102. Each of
these layers may be subjected to one or more processes that
include, but are not limited to, etching, exposure to a light
(e.g., to harden a portion of the material) and/or exposure to one
or more chemicals (e.g., to develop the unexposed portions of the
material and/or deposit a layer a material on the substrate 102)
and other process techniques including those known in the art.
Before and/or after one or more additive deposition and/or
subtractive processes (e.g., polyimide developing, resist
developing, stainless steel etching, and/or the like), the coupons
108A-108H may be analyzed by one or more sensors 114A-114D. The
sensors 114A-114D may be used to determine one or more physical
characteristics of the coupons 108A-108H including, but are not
limited to, size, height, thickness, width, diameter, conductivity,
resistance, reflectivity, adhesion, side slope, color and other
characteristics that can be used to evaluate a process. Example
sensors 114A-114D may include, but are not limited to, cameras to
determine sizes of the coupons 108A-108H, electrical probes to
measure conductivity/resistance of the coupons 108A-108H,
spectrometers to measure the thickness, reflectivity and/or color
of the coupons 108A-108H and/or an interferometer (e.g., a white
light interferometer, for example a scanning white light
interferometer) to measure a surface profile (e.g., thickness
and/or width) of the coupons 108A-108H. For example, after a resist
layer is developed, the system 100 may pause, a sensor 114A-114D
(e.g., a camera) may capture an image of a coupon 108A-108H
produced using the process, and it can be determined from the
captured image whether the coupon 108A-108H was manufactured
correctly. For other embodiments, the system need not be paused for
one or more sensors to capture an image of a coupon 108A-108H.
According to some embodiments, testing one or more coupons
108A-108H may require physical contact or even performing
destructive testing on the coupons 108A-108H. As such, the testing
of the coupons 108A-108H can either reduce or eliminate the
likelihood that flexures 106A-106L will be damaged during testing
for compliancy of the assembly sheets 104A-104I.
According to various embodiments, the physical characteristics of
the coupons 108A-108H are designed to indicate whether a portion of
the flexures 106A-106L (e.g., a dielectric layer, conductive layer
and/or the like) was manufactured correctly, whether a portion of
the flexures 106A-106L includes an abnormality and/or whether
parameters, characteristics and/or other aspects of the
manufacturing process may need to be altered before abnormal
flexures 106A-106L are produced. That is, the manufacturing process
may drift during the manufacturing of the flexures 106A-106L due to
one or more factors (e.g., chemical control, temperature, process
flow rate, expose energies and/or the like). In embodiments, one or
more coupons 108A-108H may be used to determine when the
manufacturing process begins to drift to either correct the process
before faulty or defective flexures 106A-106L, that fail to comply
with certain design specifications of the flexures 106A-106L, are
produced and/or to determine whether any faulty or defective
flexures 106A-106L have been produced.
For example, the coupons 108A-108H may include a plurality of
features that are created during the manufacturing process using
manufacturing process steps that are used to create the flexures
106A-106L. According to various embodiments, the features included
in the one or more coupons 108A-108H are configured to be more
sensitive to manufacturing process variations than the one or more
devices being manufactured using the one or more processes, such as
a flexure 106A-106L. As an example, the features of the coupons
108A-108H may be a plurality of lines that are formed of, for
example, polyimide, Cu, Ni, Au and/or the like by the additive
and/or subtractive processes used in producing the flexures
106A-106L. The lines may have a range of different widths that vary
from approximately 80 microns to 5 microns. Similar, but not
identical lines (e.g., 10 micron lines) may be created in the
manufacturing of the flexures 106A-106L during the same
manufacturing processing step (e.g., formed of the same material as
the coupon 108A-108H using the same additive and/or subtractive
processes). As such, if a test reveals that one or more of the
lines of the coupons 108A-108H include abnormalities, it is likely
that the lines of the flexures 106A-106L also include abnormalities
or that the process has deviated from its operating tolerances. As
such, it will likely be detectable that the manufacturing process
is starting to drift from one or more operating tolerances when
testing the coupons 108A-108H before the integrity of the flexures
106A-106L is affected. Accordingly, the manufacturing process can
be modified when an abnormality of a coupon 108A-108H is detected,
so that the flexures 106A-106L do not begin to have unacceptable
abnormalities that could affect the performance of the flexures
106A-106L. Examples of modifications that can be made to a
manufacturing process include, but are not limited to, the conveyor
speed that translates the substrate 102 through the manufacturing
machine 112 may be adjusted, the manifold pressure of the
manufacturing machine 112 may be adjusted, and other modifications
of one or more variables or variations used to modify a process
including those known in the art.
Other features of the coupons 108A-108H, according to various
embodiments, may be a plurality of holes formed in, for example,
polyimide, a photoresist layer, Cu, SST layer, Ni, Au and/or the
like by the additive and/or subtractive processes used in producing
the flexures 106A-106L. The holes may have a range of different
widths varying in diameter, for example from approximately 80
microns to 5 microns. Similar, but not identical holes (e.g., 10
micron holes) may be created in the manufacturing of the flexures
106A-106L during the same manufacturing processing step (e.g.,
formed in the same material as the coupon 108A-108H using the same
additive and/or subtractive processes). If, as determined by a
sensor 114A-114D, a 5 micron hole of a coupon 108A-108H is
determined to not be completely cleared and/or includes
abnormalities, then it may be determined that the one or more
portions of the flexures 106A-106L also likely include one or more
abnormalities or that the process has drifted beyond one or more
operating tolerances. As such, in addition to determining the
manufacturing process is beginning to drift before faulty or
defective flexures 106A-106L are produced, the system 100 may also
be used to determine when faulty or defective flexures 106A-106L
are produced. According to various embodiments, after making a
determination that the flexures 106A-106L likely include one or
more abnormalities, the manufacturing process can be adjusted so
that the system 100 will again produce flexures 106A-106L that do
not include any abnormalities or so that the one or more
manufacturing processes are operating within desired tolerances.
For example, one or more of the following used in manufacturing the
flexures 106A-106L and coupons 108A-108H may be adjusted: the
conveyor speed that translates the substrate 102 through the
manufacturing machine 112, the chemistry temperature of the
photolithography, the chemical concentrations used in the
photolithography, the baking and/or curing temperatures used in the
photolithography, and/or the manifold pressure of the manufacturing
machine 112 or other processes including those known in the art.
Furthermore, any faulty or defective flexures 106A-106L can be
removed from the process and either corrected or discarded, so
faulty or defective flexures 106A-106L are not sent to a user of
the flexures 106A-106L.
In embodiments, thresholds may be used to determine whether faulty
or defective flexures 106A-106L have been formed and/or whether to
adjust the process for manufacturing the flexures 106A-106L. For
example, assume a feature of a coupon 108A-108H includes an
aberration from the intended design of the feature. Further assume
the aberration of the feature only varies from the intended design
by +/-5%. With an aberration of this magnitude (i.e., +/-5%), it
may be determined that no faulty or defective flexures 106A-106L
have been produced. Furthermore, in embodiments, an aberration of
this magnitude may indicate that while aberrations do exist in the
features of the coupons 108A-108H, the process for manufacturing
the flexures 106A-106L may not need to be adjusted yet. If,
however, the magnitude of the aberration is +/-10%, then it may be
determined that no faulty or defective flexures 106A-106L have been
produced, but the process to manufacture the flexures 106A-106L may
need to be adjusted. Alternatively, if the magnitude of the
aberration is +/-15%, then it may be determined that faulty or
defective flexures 106A-106L have been produced and that the
process to manufacture the flexures 106A-106L may need to be
adjusted. The thresholds for making each of these determination may
be configurable based on the process step and/or the type of
feature of the coupon 108A-108H being tested. However, these are
only examples and not meant to be limiting.
FIG. 2 is an illustration of a top-down view of an example assembly
sheet 200 according to an embodiment. According to some
embodiments, the assembly sheet 200 may be approximately
250.times.300 mm. However, this is only an example and not meant to
be limiting. The plurality of flexures, such as the flexures
106A-106L illustrated in FIG. 1, are formed in columns 202 of the
assembly sheet 200. Each assembly sheet 200 includes one or more
borders 204. The borders 204 are used in the manufacturing process
to aid in moving the assembly sheet 200 through the process and to
protect flexures, such as the flexures 106A-106L, by adding a
stiffening structure around the plurality of flexures 106A-106L to
limit excessive bending or movement of the flexures 106A-106L and
therefore minimizing damage to the flexures 106A-106L. Proximate to
the one or more borders 204 and/or included within the one or more
borders 204 are sections where coupons, such as coupons 108A-108H
as illustrated in FIG. 1, can be formed. As stated above, the
coupons 108A-108H can be tested by sensors (e.g., the sensors
114A-114D depicted in FIG. 1) to determine whether the flexures
106A-106L include abnormalities.
Additionally or alternatively, the coupons 108A-108H can also be
formed at other locations of the assembly sheet 200 than the
borders 204. For example, the coupons 108A-108H may be formed
between the one or more columns 202 of the flexures 106A-106L. As
another example, the coupons 108A-108H may be formed between rows
of the flexures 106A-106L, including but not limited, formed on the
carrier strips 206 to which the flexures 106A-106L are
connected.
FIG. 3 is an illustration of a top-down view of a portion 300 of a
border, such as a border 204 illustrated in FIG. 2. The portion 300
includes a plurality of different types of coupons 302A-302E. Each
different type of coupon 302A-302E includes one or more distinct
features that are tested by the sensors, such as sensors 114A-114D
illustrated in FIG. 1. Various embodiments of coupons 302A-302E are
described in more detail in relation to FIGS. 4-8 below. The
collection of different types of coupons 302A-302E depicted in FIG.
3 may be a single coupon, such as a one of the coupons 108A-108H
illustrated in FIG. 1, that are formed near a border of an assembly
sheet, such as an assembly sheet 104A-104I illustrated in FIG.
1.
FIG. 4 is an illustration of exemplary coupons 402, 404 according
to some embodiments. Each of the coupons 402, 404 may be
incorporated a single coupon of the coupons, such as coupons
108A-108H illustrated in FIG. 1. The coupon 402 includes one or
more long conductors 406. To test the coupon 402, electrical probes
can probe each end of the one or more long conductors 406 to
measure resistance of the coupon 402. Changes in the width of the
conductor may create large changes in resistance of the coupon 402.
That is, the measured resistance can be used to determine
uniformity of the height and the width of the one or more long
conductors 406. According to various embodiments, the height and
the width of the conductors can also be determined using a vision
test (e.g., using a sensor that is a camera). The results of these
tests can determine how well the conductive portions of the
flexures 106A-106L (of FIG. 1) are being formed. If an aberration
of the coupon 402 is determined, the process for manufacturing the
flexures, such as flexures 106A-106L illustrated in FIG. 1, may be
adjusted to prevent faulty or defective flexures 106A-106L from
forming and/or to determine whether faulty or defective flexures
106A-106L have been manufactured.
The coupon 404 includes a plurality of ground features coupled
together. When manufacturing flexures, such as flexures 106A-106L
illustrated in FIG. 1, each flexure 106A-106L may have anywhere a
number of ground features 408 (e.g., 2-10 ground features). The one
or more ground features 408 of the flexures 106A-106L are designed
to have a very low resistance. According to various embodiments,
the ground features 408 may be plating from a first layer of the
flexure (e.g., the trace layer) through a hole in a second layer of
the flexure (e.g., the dielectric layer) and into contact with a
third layer of the flexure (e.g., the SST layer). Additionally or
alternatively, the ground features 408 may also be conductive
adhesion holes. Ground features are explained in more detail in
U.S. Pat. No. 9,093,117, entitled "Ground Feature for Disk Drive
Head Suspension Flexures," the entirety of which is incorporated
herein by reference for all purposes.
While the ground features of the flexures are designed to have very
low resistance, during the manufacturing of the flexures, such as
flexures 106A-106L illustrated in FIG. 1, the resistance of the
ground features may gradually increase. By coupling a plurality of
ground features (e.g., 10-30 ground features) together in a coupon
404, it can be determined, using a sensor, such as a sensor
114A-114D illustrated in FIG. 1 (e.g., an electrical probe),
whether the resistance of the ground features is beginning to
increase, has a fault and/or a high resistance due to inadequate
plating. If any one of the ground features has a fault, it is
likely one or more of the ground features of the flexures 106A-106L
also includes a fault.
FIG. 5 illustrates coupons 502, 504 according to various
embodiments. Coupon 502 is a spectrometer strip. In embodiments,
spectrometer strips may be used to manufacture the flexures, such
as flexures 106A-106L as illustrated in FIG. 1, using a wet coating
process. During the wet coating process, the substrate, such as the
substrate 102 as illustrated in FIG. 1, is being translated through
the manufacturing machine, such as the manufacturing machine 112
illustrated in FIG. 1, at a translation speed. Using a
spectrometer, the thickness of the coupon 502 and any residues on
the coupon 502 may be determined. By determining the thickness of
the coupon 502, it can be determined whether one or more layers
(e.g., spectrometer strips and/or a dielectric layer) are applied
to the appropriate thickness by the manufacturing machine 112 at
the translation speed of the substrate 102. If the coupon 502 does
not have an appropriate thickness, the translation speed of the
substrate 102 may be decreased. Moreover, the manufacturing process
steps may include cleaning one or more surfaces of the flexure. As
such, by determining whether any residues are on the coupon 502 can
determine whether the one or more surfaces of the flexures
106A-106L are being adequately cleaned.
FIG. 5 also includes a plurality of coupons 504, which are shown to
indicate that different coupons may have a different scale with
respect to other coupons, such as various embodiments described in
more detail with respect to FIGS. 7 and 8.
FIG. 6 illustrates a coupon 602 according to an embodiment. The
coupon 602 may include a plurality of features 604A-604E wherein
the surface profile (e.g., the thickness and/or width) of the
plurality of features 604A-604E are determined using interferometry
(e.g., white light interferometry). The coupon 602 may include a
plurality of coating liquids formed on layers that are used to
produce the flexures 106A-106L. For example, a coating liquid
("CL") may be applied to a conductive layer and/or a dielectric
layer of the flexures, such as flexures 106A-106L illustrated in
FIG. 1. According to various embodiments, the CL may flow off the
layer of the flexures 106A-106L that the CL is intended to coat.
The amount of CL that flows off may depend on one or more of, for
example, the size of the layer that is being coated, the type of
layer that is being coated, the liquid that is being used as the
CL, temperature of the CL, ambient temperature of the layer and CL
and/or the like. By applying a CL to various widths of features
604A-604E that, according to some embodiments, are made of
different types of materials and determining the surface profile of
the CL (i.e., the features 604A-604E), it can be determined whether
the one or more CL layers of the flexures 106A-106L are being
applied or removed to result in features having the appropriate
widths, heights or depths.
FIG. 7 illustrates a coupon 702 according to various embodiments.
The coupon 702 includes a plurality of features 704-718. If one or
more of the features 704-718 includes an aberration, as sensed by
the sensors, such as sensors 114A-114D illustrated in FIG. 1, then
the manufacturing process may be adjusted and/or it may be
determined that one or more of the flexures, such as flexures
106A-106L illustrated in FIG. 1, are faulty or defective.
Feature 704 includes a series of holes with a range of different
diameters that may be formed in, for example, polyimide, a
photoresist layer, Cu, SST layer, Ni, Au and/or the like by the
additive and/or subtractive processes used in producing the
flexures 106A-106L. According to various embodiments, feature 704
is configured to indicate a minimum adhesion resist or minimum
cleared plating for a process. The sensors 114A-114D, according to
various embodiments, may sense the smallest hole that is being
cleared out consistently, which provides an indication at how well
the manufacturing process used to produce the flexures 106A-106L is
working. As stated above, if the flexures 106A-106L include holes
that are 10 microns, the holes of the features 704 may be smaller
than 10 microns to determine whether the manufacturing process is
drifting before faulty or defective flexures 106A-106L are
produced.
Feature 706 includes a series of dots that are formed of, for
example, polyimide, Cu, Ni, Au and/or the like by the additive
and/or subtractive processes used in producing the flexures
106A-106L on the coupon 702. According to various embodiments,
feature 706 is configured to indicate a minimum resist cleared or
minimum adhesion plating for a process. The sensors 114A-114D may
sense what the smallest dots that are being adhered to the surface
of the coupon 702 using techniques including those described
herein, as determined by the presence of the smallest dot on the
surface of the coupon 702.
Features 708, 712 include vertical and horizontal troughs,
respectively, having a range of different widths and spacing's that
are formed in, for example, polyimide, a photoresist layer, Cu, SST
layer, Ni, Au and/or the like by the additive and/or subtractive
processes used in producing the flexures 106A-106L. According to
various embodiments, features 708, 712 are configured to indicate a
minimum resist cleared or a minimum adhesion plating vertical and
horizontal, respectively, for a process. The sensors 114A-114D may
sense the smallest trough 708, 712 that is being cleared out
consistently using techniques including those described herein,
which provides an indication at how well the manufacturing process
used to produce the flexures 106A-106L is working.
Features 710, 714 include vertical and horizontal lines,
respectively, having a range of different widths and spacings that
are formed of, for example, polyimide, Cu, Ni, Au and/or the like
by the additive and/or subtractive processes used in producing the
flexures 106A-106L on the coupon 702. According to various
embodiments, features 710, 714 are configured to indicate a minimum
resist line or a minimum plating cleared, respectively, for a
process. The sensors 114A-114D may sense the smallest line that is
being applied consistently to the coupon 702 using techniques
including those described herein, which provides an indication at
how well the manufacturing process used to produce the flexures
106A-106L is working. 708, 712. According to various embodiments,
for example, the range of widths of the features 704-718 may be
from 5 microns to 80 microns.
Since the substrate, such as a substrate 102 illustrated in FIG. 1,
is being translated through the manufacturing machine, such as a
manufacturing machine 112 illustrated in FIG. 1, in one direction,
chemicals may be applied to the substrate 102 either in the same
direction or perpendicular to the direction that the substrate 102
is being translated. As such, variances between the vertical 708,
710 and horizontal features 712, 714 that are being cleared and/or
applied may be different, which is why both vertical 708, 710 and
horizontal 712, 714 troughs and lines are tested, according to some
embodiments. Similar to the features 704, if the flexures 106A-106L
include troughs or holes that are 10 microns wide, the troughs or
holes of the features 708-714 may be smaller than 10 microns to
determine whether the manufacturing process is drifting before
faulty or defective flexures 106A-106L are produced.
Feature 716 is a registration feature to a previous layer. The
feature 716 includes an outside rim 722, which is from one layer,
and an inner circle 724, which is from a different layer. The
feature 716 will be measured using a sensor 114A-114D to determine
how well the two layers are registered to each other. How well one
layer is registered to another layer is the degree to which the
inner circle 724 of the feature 716 is offset from a desired
central location in the outside rim 722 of the registration
feature.
Feature 718 is a star shaped pattern which exaggerates the side
slope of features of the flexures 106A-106L. The side slope of a
feature is the angle of a side of the feature. That is, a feature
(e.g., a polyimide layer) of the flexures 106A-106L that is etched
by the additive and/or subtractive processes used to produce the
flexures 106A-106L may not have a side that is perpendicular to a
surface of the substrate. The angle relative to a perpendicular of
a feature is referred to as the side slope. As such, by testing the
side slope of a feature 718 that exaggerates the side slope of the
flexures 106A-106L, it can be determined that the side slope of the
features of the flexures 106A-106L are consistent. To sense the
side slop, a vision system may be used, which is a type of sensor,
such as sensors 114A-114D illustrated in FIG. 1.
Feature 720 is a calibration pad which can be used to calibrate a
vision system that is a type of sensor, such as those included in
the sensors 114A-114D. The feature 720 (i.e., the calibration pad)
can be used to determine the focal height and light intensity of
the vision system based on the reflectivity of the calibration pad.
The feature 720 can be made of the same material as the layer that
is being formed on the substrate, such as a substrate 102
illustrated in FIG. 1. For example, the feature 720 may be made of
a dielectric, conductive layer, or other material known in the art
including those described herein. This will increase the likelihood
that the feature 720 has the same reflectivity calibration (which
may change due to topographic changes, surface oxide conditions,
etc.) as the layer that is being formed on the substrate 102. In
embodiments, the vision system may be a greyscale vision
system.
FIG. 8 illustrates a plurality of the coupons 800 according to
various embodiments. For some embodiments, the plurality of coupons
800 include features similar to those described in reference to
those illustrated in FIG. 7. As stated above, multiple layers may
be applied to the substrate, such as substrate 102 illustrated in
FIG. 1, when manufacturing the flexures, such as flexures 106A-106L
illustrated in FIG. 1. After each layer of the flexures 106A-106L,
a coupon 802A-8020 of the plurality of coupons 800 may be added to
the layer. Each coupon 802A-8020 that is formed may correspond to
the specific manufacturing process for that layer of the flexures
106A-106L. For example, if a first layer of the flexures 106A-106L
is a polyimide layer, a first coupon (e.g., coupon 802A) may be
formed, on the border 204 (of FIG. 2) of the assembly sheet 200 (of
FIG. 2), using the same manufacturing process step to produce the
polyimide layer of the flexures 106A-106L. That is, the coupon 802A
may include polyimide features (e.g., a range of holes with
different diameters, a range of dots with different diameters, a
range of troughs with different widths, a range of lines with
different widths and/or the like) that are similar to but of
different dimensions than the polyimide layer of the flexures
106A-106L. As such, the resolution/adhesion of each layer may be
determined using the respective coupons 802A-8020 for each layer.
The numbers 804A-0 for each respective coupon 802A-8020 may
indicate the layer to which the coupon 802A-8020 pertains. For
example, coupon 802A may be the coupon included on the first layer,
coupon 802B may be the coupon included on the second layer,
etc.
Furthermore, including a respective coupon 802A-8020 for each layer
that is produced during the manufacturing of the flexures, such as
flexures 106A-106L illustrated in FIG. 1, may also determine
whether the resolution/adhesion of the coupon 802A-8020 is affected
when combined with other layers that are produced during the
manufacturing of the flexures 106A-106L. For example, a coupon
802A-8020 produced on a conductive layer that is formed on top of a
polyimide layer may have defects that are not detected when a
coupon is formed on top of a conductive layer that is not formed on
top of a polyimide layer. As such, stacking coupons 802A-8020 on
multiple layers may provide a better indication of the quality of
flexures 106A-106L produced during the manufacturing of the
flexures 106A-106L since the flexures 106A-106L include multiple
layers stacked on one another.
Additionally or alternatively, after each layer, all the
manufacturing process steps that are used to produce the flexures
106A-106L may be used to form coupons 802A-8020. For example, even
though a polyimide layer may be formed during a layer, the coupons
802A-8020 may also include features corresponding to a conductive
trace layer.
FIG. 9 is a diagram of a data management process flow 900 according
to an embodiment. According to various embodiments, the process
flow 900 may include receiving a signal identifying an assembly
sheet including a formed coupon (902). Each assembly sheet may have
its own barcode, which is scanned using sensors including those
described herein. After each manufacturing process step, the
barcode for each assembly sheet may be read by a barcode scanner
(904). According to various embodiments, one or more of the sensors
114A-114D may be barcode scanners.
Each time a barcode for an assembly sheet is scanned, the results
of any scans/tests performed by the sensors on the coupons may also
be received (906). From each of the tests, it can be determined
whether the received result indicates whether one or more coupons
include aberrations and, therefore, the flexures possibly include
faulty or defective flexures, as well. All this information may be
tracked during the course of producing the flexures. If it is
determined that an assembly sheet may include faulty or defective
flexures, additional inspection of the assembly sheet may be
performed and/or the assembly sheet may be rejected. As such, each
assembly sheet may be tracked through the entire process.
Various modifications and additions can be made to the exemplary
embodiments discussed without departing from the scope of the
present invention. For example, while the embodiments described
above refer to particular features, the scope of this invention
also includes embodiments having different combinations of features
and embodiments that do not include all of the described features.
Accordingly, the scope of the embodiments is intended to embrace
all such alternatives, modifications, and variations as fall within
the scope of the claims, together with all equivalents thereof.
While the disclosed subject matter is amenable to various
modifications and alternative forms, specific embodiments have been
shown by way of example in the drawings and are described herein.
The intention, however, is not to limit the disclosure to the
particular embodiments described. On the contrary, the disclosure
is intended to cover all modifications, equivalents, and
alternatives falling within the scope of the disclosure as defined
by the appended claims.
As the terms are used herein with respect to ranges of measurements
(such as those disclosed immediately above), "about" and
"approximately" may be used, interchangeably, to refer to a
measurement that includes the stated measurement and that also
includes any measurements that are reasonably close to the stated
measurement, but that may differ by a reasonably small amount such
as will be understood, and readily ascertained, by individuals
having ordinary skill in the relevant arts to be attributable to
measurement error, differences in measurement and/or manufacturing
equipment calibration, human error in reading and/or setting
measurements, adjustments made to optimize performance and/or
structural parameters in view of differences in measurements
associated with other components, particular implementation
scenarios, imprecise adjustment and/or manipulation of objects by a
person or machine, and/or the like.
* * * * *